1. Field of the Invention
The present invention relates to dobbies and other mechanisms for forming the shed in weaving machines, and more particularly to the coupling of the heddle frames to the cables or other transmission elements intended for moving them.
2. History of the Related Art
A large number of different systems have been proposed in practice, of which certain are arranged to allow the adjustment of the heddle frames in height, and reference may be made in particular to documents FR-A-970 624 (TESSRAION), BE-A-521 289 (LINDAVER DORNIER), EP-A-325 547 (STAUBLI) and EP-A-161 375 (SULZER).
Patent FR-A-2 617 204 to STAUBLI discloses a coupling device comprising conjugate male and female members in the form of tenons and mortises, some of which are fixed to the uprights of the frame, the others to the transmission elements. The members fixed to the uprights are split parallel to the plane of the frame so as to be traversed by the transmission elements and to form, on either side of the transmission elements, contact surfaces between the tenions and mortises for the transmission of forces.
Such an arrangement is most advantageous as it makes it possible to reduce to a considerable extent, or even virtually eliminate, the overhang existing between each of the uprights of the heddle frame and the axis of the cable which ensures displacement thereof. Consequently, the two conjugate members of each device require no reciprocal fixation, their fit with reduced clearance in the manner of a tenon and mortise being sufficient to ensure, alone, the transmission of the drawing efforts.
In the embodiment shown and described in the Patent mentioned above, the member which is intended to be secured to the transmission element was provided with a mechanism including a jaw provided with two opposite oblique faces adapted to cooperate with an oblique ramp formed on one and the other of two pushers assembled to each other by a locking screw. Although such a structure allows precise adjustment of the heddle frame with respect to the transmission element, the construction is nonetheless relatively complex and expensive.
Furthermore, with a view to avoiding any parasitic lateral displacement of the member fixed on the transmission element or cables during operation of the weaving loom, particularly under the effect of torsional forces exerted on the cables, it was necessary to provide the member in question with a heel element whose free end is engaged with clearance in the opening of a fixed vertical slide. It is clear that this arrangement nonetheless complicates the whole assembly of the heddle frames.
It is a principal object of the present invention to overcome the drawbacks set forth hereinabove, while conserving the advantages of the devices according to Patent FR-A-2 617 204 (STAUBLI).